1. Field of the Invention
The present invention relates to a reel, on which a recording tape such as a magnetic tape or the like that is principally employed as a recording/replaying medium of a computer or the like is wound, and to a recording tape cartridge equipped with the reel.
2. Description of the Related Art
A recording tape such as a magnetic tape or the like that is used as a data recording/replaying medium (data backup) for computers or the like is wound onto a reel made of synthetic resin. A recording tape cartridge that accommodates one such reel in a case has been known heretofore. The reel of this recording tape cartridge may be a reel with a structure in which, for example, a hub around whose outer periphery face the recording tape is wound and an upper flange and a lower flange that retain recording tape width direction end portions of the recording tape are formed as respectively separate bodies (a three-piece structure) (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2007-335032).
A reel with the three-piece (three-component) structure described in JP-A No. 2007-335032 has a structure in which an annular extension portion formed at an inner periphery edge portion of the upper flange and an annular extension portion formed at an inner periphery edge portion of the lower flange are each welded to projection portions protruding from an inner periphery face of the hub. However, in this reel, the annular extension portions are tightly fitted to the inner periphery face of the hub. Therefore, if the hub is deformed inward in the radial direction by pressure due to a recording tape being wound thereon, the annular extension portions may follow this deformation and the upper flange and lower flange may be deformed.